I'm really enjoying iOS 7 on my 4S and it's running nice and smooth, but it is SHREDDING my battery! I'm not losing any sleep over it right now because I plan to move to the 5S soon anyway, but it worries me that the 5S may wind up being just as crummy a battery life as the 4S has always been. I mean, I thought the 4S battery was bad before, but now I go from 100 to 55% in a matter of two hours of moderate usage. If I wasn't upgrading my phone anyway I'd be up in arms.
And yes, I will dig through the settings and look for a culprit, and blahblahblah, but generally I take offense to the whole "Well if you would just turn the brightness down, shut off location services, turn off notifications, never use maps, stop playing music, and never stream anything, then you'd be fine" type of rationalization. There's no reason to have such a fabulous phone if you have to turn all the features off to use it.